The invention provides multifunctional catalytic
cracking strengthening additive which comprises a
rare earth organic compound,
heteropoly acid (and salt thereof), chemical inhibitor,
solvent, and the like and has the functions of resisting oxidation and preventing from scorch, dispersing, increasing the acid center, passivating the
metal, and the like. When being added into a catalytic
cracking lifting
pipe reactor, the multifunctional catalytic
cracking strengthening additive can inhibit the generation of secondary reaction such as thermal
cracking reaction,
dehydrogenation condensation reaction, and the like, reduces the generation of side products of net gas,
coke,
hydrogen, and the like, and improves the yield coefficients of products with high added values, such as
liquid gas (especially propylene),
gasoline and diesel. The catalytic cracking strengthening additive has the function of
metal deactivator and can replace the
metal deactivator, therefore, the
metal deactivator needs not to be added after the catalytic cracking strengthening additive is added. The invention has the function of resisting oxidation and preventing from scorch, can inhibit a lifting
pipe and a
settling vessel from being coked and prevent a
reaction system from scale deposit, thereby being multifunctional catalytic cracking strengthening additive.